Question
Where do we get the concept of saving the best for last?
Answer
The concept is derived from Gen. 33:2, where Jacob (when he met Esau) put his concubines and their children first, and Leah and her children after them, and Rachel and Joseph last. Rashi uses the phrase "acharon acharon chaviv" in commenting on that verse; it is also used in Bereishis Rabbah 76:11.